Re: Re: Abbreviated keys for Numeric

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От Andrew Gierth
Тема Re: Re: Abbreviated keys for Numeric
Дата
Msg-id 87ppa1f8me.fsf@news-spur.riddles.org.uk
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Ответ на Re: Abbreviated keys for Numeric (was: Re: B-Tree support function number 3 (strxfrm() optimization))  (Peter Geoghegan <pg@heroku.com>)
Ответы Re: Re: Abbreviated keys for Numeric  (Peter Geoghegan <pg@heroku.com>)
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>>>>> "Peter" == Peter Geoghegan <pg@heroku.com> writes:
Peter> What I find particularly interesting about this patch is that itPeter> makes sorting numerics significantly
fasterthan even sortingPeter> float8 values,
 

I get a much smaller difference there than you do.

Obvious overheads in float8 comparison include having to check for NaN,
and the fact that DatumGetFloat8 on 64bit doesn't get inlined and forces
a store/load to memory rather than just using a register. Looking at
those might be more beneficial than messing with abbreviations.

-- 
Andrew (irc:RhodiumToad)



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